NUTS AND VOLTS

Posted in: Nuts and Volts

Mouser Adds Adafruit to Its Open Source Lineup

July 15 

Mouser Electronics, Inc. announced that it has signed a global distribution agreement with Adafruit. Adafruit was founded in 2005 by Massachusetts Institute of Technology (MIT) engineer Limor "Ladyada" Fried. Adafruit offers unique and fun DIY electronics, kits, andopen-source hardware that turn everyday objects into high-tech prototypes suitable for education and advanced production concepts.

   

 


Mouser Electronics will offer same-day shipping on the Adafruit product line, including the FLORA and GEMMAwearable electronic platforms. These small but powerful boards incorporate programming based on the Arduinointegrated development environment (IDE) through USB interface to give designers and entry-level makers alike the ability to easily create prototypes of wearable devices. The FLORA board includes 14 sewing tap pads for attachment and electrical connections on a 1.75 in. diameter body, and the even smaller GEMMA board puts its six sewing tap pads on a 1.1 in. diameter body.

Mouser will also stock the Adafruit HUZZAH ESP8266 breakout board, a tiny WiFi microcontroller based on the ESP8266 80MHz microcontroller. This breadboard-friendly module makes adding WiFi to projects easy with onboard WiFi antenna, I/O pins, and level shifting.

"Mouser is excited about this new partnership with Adafruit," said Russell Rasor, Mouser Vice President, Supplier Management. "With the growing popularity of the Maker and DIY movement, Adafruit will be a welcome addition to our lineup for open-source products. Customers across the globe now have access to an expanded offering of innovative products designed by experts with a passion for electronics education and inspiring the next generation of engineers."

"Mouser's global reach enables us to extend our customer base to offer powerful and easy-to-use products to people of all skill levels," said Limor "Ladyada" Fried, founder and engineer. "Known for their best-in-class distribution, renowned service and exceptional customer reach, Mouser is a valued strategic partner for us. We look forward to much success."

To learn more, visit http://www.mouser.com/adafruit/.


Posted on 07/15 at 8:00 am

Posted in: Developing Perspectives

Vintage Repair

July 15  Bryan Bergeron

I’m in the middle of overhauling a vintage Singer 201-2 sewing machine, manufactured in the US in 1940. As I expected, the motor brushes need replacing, the oldfashioned leaf switch controlling the light is — at best — intermittent and needs a good cleaning, and the cottoninsulated wire is begging to be updated to fireproof silicon insulated wire. Old appliances — void of microcontrollers or even simple semiconductors — are a pleasure to tear down and rebuild. They’re fun as a solo weekend project, or, if you have someone you want to teach basic mechanics and electricity to, they make a good two or three weekend project. Even bringing an old toaster back to life can provide a sense of satisfaction.


Back to the Singer, there’s always more involved in a vintage repair than meets the eye. These old sewing machines require regular lubricating and cleaning like any other fine metal equipment. I’ve tried just about every grease on the market, and have come to rely on Tri-Flo clear grease. It’s a synthetic grease that’s fairly odorless, relatively inexpensive, and easy to come by. Just make certain you remove all of the old organic grease before you apply the Tri-Flo. The combination of old and new grease doesn’t perform well.

One of the unfortunate characteristics of lighted appliances from the middle of the last century is that they relied on inefficient 110V incandescent bulbs. The Singer uses a miniature 15W bulb that gets extremely hot — hot enough to blister the paint on the bulb holder. I’ve solved that problem by replacing the incandescent with a more efficient, much cooler LED version. An unanticipated advantage of moving to LED lighting is that the light is nearly pure white as opposed to yellow. You can find LED bulbs at Amazon, 100bulbs.com, and, of course, homedepot.com.

Replacing frayed power cords can be a challenge — especially when the appliance is designed for a non-polarized two-pronged connection to the mains. Arbitrarily connecting a three-pronged plug can be a hazard — especially on an appliance with a metal chassis. Unless you’re familiar with electrical code — as well as how your house is wired — I’d stick with the original wiring diagram. Do replace the brittle plastic cord with modern flexible cord. I’ve had good luck with non-polarized cords from both Amazon and Walmart.

Switches — especially power switches — are the most problematic components in a vintage repair. It’s usually easy enough to replace a toggle switch with a garden variety version, but it’s at the cost of destroying the “vintage” feel of the appliance. Take the Singer sewing machine switch. The toggle is a distinctive white Bakelite, and the mechanical aspect of the switch is almost two inches long. I was lucky enough to find a new old stock (NOS) replacement on eBay. Otherwise, I would have been forced to substitute a miniature toggle switch for the classic Bakelite toggle. I’ve found a great source of old fashioned switches is guitar supply houses and local music stores — especially stores that cater to the tube amp crowd.

So, next time you walk past a yard sale, check out the vintage electrical items. There’s always something to learn from a teardown, even if you have no need for the actual item. NV


Posted on 07/15 at 9:35 am

Posted in: Nuts and Volts

The BBC micro:bit

July 15 

Groundbreaking collaboration between 29 partners including ARM, Barclays, BBC, element14, Freescale, Lancaster University, Microsoft, Nordic Semiconductor, Samsung, ScienceScope, Technology Will Save Us and the Wellcome Trust to give a pocket-sized computer to every year 7 child in the UK for free; ambition to inspire digital creativity and develop a new generation of tech pioneers

 


The The BBC and partners today unveiled the BBC micro:bit – a pocket-sized, codeable computer that allows children to get creative with technology. In the BBC’s most ambitious education initiative for 30 years, up to 1 million devices will be given to every 11 or 12 year old child in year 7 or equivalent across the UK, for free.

 BBC micro:bit is a pocket-sized computer that you can code, customise and control to bring your digital ideas, games and apps to life. Measuring 4cm by 5cm, and designed to be fun and easy to use, users can create anything from games and animations to scrolling stories at school, at home and on the go - all you need is imagination and creativity. The BBC micro:bit is completely programmable. That means each of its LEDS can be individually programmed as can its buttons, inputs and outputs, accelerometer, magnetometer and Bluetooth Smart Technology.

 

to read more about the BBC micro:bit, visit the BBC Website


Posted on 07/15 at 8:35 am

Posted in: Nuts and Volts

TS-7970 i.MX6 Powered Single Board Computer Now Sampling

June 15 

Fountain Hills, AZ June 19, 2015 – Technologic Systems Inc., an embedded systems solutions company, has announced they will be releasing limited samples of their new high end, Single Board Computer (SBC), TS-7970 for engineering and early prototypes. The TS-7970 can fulfill a wide variety of embedded system requirements with high performance components, like a 1.2 GHz Single or Quad Core Cortex A9 ARM CPU, 512 MB to 2 GB DDR3 RAM, 4 GB eMMC Flash Storage, microSD card slot, Gigabit Ethernet, and available Wireless 802.11 b/g/n and Bluetooth radio. Full descriptions, pictures, and resources, including manuals and schematics, for the TS-7970 can be found on the Technologic Systems' TS-7970 product page.


TS-7970 Bottom View

 

The TS-7970 is a high performance single board computer based on the Freescale i.MX6 CPU which implements the ARM® Cortex™-A9 architecture clocked at 1 GHz (Single or Quad Core) and paired with with 1GB or 2GB of DDR3 RAM. Several industry standard interfaces and connections such as dual Gigabit Ethernet, WiFi and Bluetooth, USB, SATA II, and more make the TS-7970 a great fit for nearly any embedded systems application. A wide variety of software platforms are available including Linux and QNX (with Android and Windows support coming soon) for flexibility in matching your embedded system requirements.

  • High Performance Embedded with Solo or Quad Freescale i.MX6 ARM CPU
  • Wireless Connectivity for Remote Access and IoT-like Applications
  • Protect Valuable Data with Robust and Reliable Storage Solution
  • High Speed Industry Standard Connectors like Gigabit Ethernet and SATA II
  • Engineered for Rugged, Industrial Environments

 

[Source] embeddedarm.com


Posted on 06/15 at 10:59 am

Posted in: Nuts and Volts

BeagleSat - Enabling accurate magnetic field measurements on CubeSats

June 15 

Magnetic field measurements play an important role in Earth-orbiting satellites, such as attitude determination and scientific instrument pointing. Unless built specifically for high accuracy measurements, satellites usually come with significant magnetic sources of errors that severely degrade measurement accuracy. This GSoC project aims to implement algorithms that enable low-cost high quality magnetic field measurements on smaller spacecraft without booms using the BeagleBone platform.



Posted on 06/15 at 9:01 am

Posted in: Developing Perspectives

Change the World

June 15  Bryan Bergeron

While there’s satisfaction from getting an LED to blink five times in a row in response to a button press, it isn’t going to change the world — that is, unless you set your goals higher. It’s easy to lose track of the fact that electronics have changed human existence in only a few decades. Computers, TV, satellites, space exploration, drones, cell phones, robots, aviation, and modern automobiles are but a few examples. Against that backdrop, there’s a vast vacuum for experimentalists and engineers to fill. What I’m suggesting is that you take your knowledge of electronics — whatever your level of expertise — and focus it towards solving a meaningful problem.


I’m not suggesting you forgo experimenting with the basics such as triggering a microcontroller, but that you have a much larger purpose in mind — something to work toward other than simply acquiring knowledge for its own sake. For better or worse, there seems to be no end of problems to be solved.

Take the recent drought in California that negatively affects everyone in Silicon Valley. How can you leverage your knowledge of electronics to solve that dilemma? I don’t have the answer, of course, but I’d start with looking for energy efficient means of desalination, perhaps some means of remotely monitoring the hydration of crops, and perhaps image processing techniques that can be applied to readily available satellite telemetry to track water consumption.

I’m sure you can think of a few dozen other areas to explore. The point is, there is no end of problems that you can address with your skills as an experimentalist. History suggests that your odds of changing the world are better if you have a clear vision of what you’re going to accomplish, versus simply stumbling upon it. Of course, there are examples of accidental discoveries, but even then you have to be aware of the problems that need solving.

You might be reading this thinking what can you do at night in your basement, armed with a soldering iron and a few hundred parts? Well, others have done a great deal with much less computing power than is available on a common microcontroller. But it’s a fair comment. Fortunately, thanks to the Internet and other communications means available, there’s no need to go it alone.

Start something or find a group with a worthwhile cause and join it. If money is a hurdle, then consider crowdfunding. Look for internships or summer jobs with companies addressing problems you want to solve or that at least get you part of the way there.

Finally, if you’re young, seek out a mentor. I’ve been fortunate to find several over the years — each with a different perspective and skill set. Conversely, if you’re older and experienced, become a mentor. Leverage your experience with a younger, less experienced and possibly more energetic student. Either way, it tends to be a winwin situation. Go ahead, change the world. I dare you. NV


Posted on 06/15 at 3:19 pm

Posted in: Featured Article

Bling Up Your 4th Of July With A Set Of Custom SMT Earrings

June 15  Ronald Newton

Of all the articles I have written, it seems that the most popular one was the December 2014 Christmas Earrings project. I received a ton of emails asking me to make other types. I thought it was interesting that the version designed using a microprocessor and surface-mount (SMT) components was far more popular than the simple one using through hole parts.


Since the Fourth of July is coming, I thought this would be the perfect time to introduce some new designs for other holidays and occasions, except this time I would make the earrings adaptable. These new circular versions include fireworks, a Jack o’ lantern for Halloween, and the timeless happy face that can actually change expressions — sad, happy, mischievous, winking, surprised, disapproving, etc.

The three versions discussed here will all use SMT components. It really won’t be too difficult, and you won't need a reflow oven.

Fireworks Jack O'Lantern Emoticon


One thing I want to bring your attention to is a new tool which I think is a must-have for working with SMT. Surface-mount capacitors don't have markings and are easy to get mixed up if spilled. Our friends at SparkFun have released a new combo set with a probe and tweezers that attach to multimeters. They work fine from 1206 to 402 SMT components. When connected to the diode mode of a DVM, you can easily discover the cathode of an LED. Place it on a capacitance meter and instantly you’ll see the unknown value of a capacitor. It works well with components on a board, as well. These cool units sell for under $6. 

The fireworks adaptation starts out as a sputtering fuse, shoots up in the sky, explodes, and then turns red, white, and blue. Next, it displays all three colors together, and finally sputters out.  

The Jack o’ lantern has flashing red eyes and its face changes. Maybe next time, I will make him giggle with a sound board. 

The emoticon earring can be like a mood ring. Or, you could even use it as an IQ test for people to figure out how you’re feeling. Emoticons can be dated back to the 19th century and are used throughout the world. In Japan, they are known as " kaomoji." The "smiley face" was drawn in 1963 by Harvey Ball and is still popular. 

All three sets of earrings measure 1.3 " in diameter and are round. They weigh five grams, including the battery. Each earring uses a CR1225 lithium battery which should last for many hours. 

The three sets of earrings have 24 LEDs set to patterns (the Jack o’ lantern only uses 19). The earrings employ 805 LEDs and let the mind connect the dots Believe it or not, they are not all on at the same time but are multiplexed, giving the appearance otherwise. Eight ports provide the positive voltage to the LEDs, and three ports switch their cathodes to ground. By alternating the ground and the positive output, you only need 12 ports to drive the 24 LEDs. 

The boards were drawn using ExpressPCB free software (www.expresspcb.com) and can be found on the Nuts and Volts website download. N&V has a complete kit with pre-programmed microprocessors which make it easy for the novice to put together. Make sure you check the website's "Hints and Tips" for any errata. The ASM files are also located there. 

You will need a small tipped soldering iron with fine solder, a pair of tweezers (I use curved), and small solder braid for solder bridges (if any). There are no holes to drill. 

HOW IT WORKS

Refer to the schematic in Figure 1. It is a general schematic for all three versions. As mentioned, the Jack o’ lantern only uses 19 LEDs. The microprocessor is the heart of the project and runs at 4 MHz. For each earring style, it uses a progressive code to tell which LED to turn on and which ones to turn off. Eight 150 ohm resistors limit the current to the LEDs.  

FIGURE 1. General schematic for all three versions


I used a Microchip PIC16F627A. It can sink/source 25 mA per port and up to 200 mA for the whole chip. It has 18 pins and is known as an SOIC mount, which keeps it small but very easy to solder. Since the LEDs are limited to 20 mA, this is actually ideal since it eliminates the need for extra transistors for the control circuit which just adds voltage drops. Running at three volts, a current-limiting resistor will hold down the current to the LEDs to below 20 mA when pulsed. You do have to be careful about picking the LEDs, though. I made the mistake of using the cheapest white versions I could find, only to discover that it needed 3.6 volts to function.  

Once an LED is called to be turned on, its cathode is grounded and a positive voltage is applied via a resistor to its anode. In the programming, I use the general call, "Call Clear" which resets all the cathodes and anodes to ground. This insures all the LEDs are off. The next LED is then turned on, and so on, and so forth. 

The LEDs turn on and off at approximately  6.6 kHz — well above 60 Hz, which is the persistence of vision (refer to the December 2014 issue for more discussion of this phenomenon).

BUILDING THE EARRINGS

GENERAL

Use a one inch strip of double-sided tape and place it on the bench. Stick a board to the tape. I use another piece of tape for placing the surface-mount components on, so I can orient them. I recommend Tacky flux to hold the LEDs on the board. I'm presently using "Quick Chip Tacky Flux" SMD4300TF which is water soluble. When placing an SMT on a board, I don't use any solder as there is usually enough on either the component or pad on the board to tack the SMT. Hold the component with a pair of tweezers and touch the soldering tip to both the component and the pad for about three seconds. I actually tacked all three types of earrings without using any extra solder. Make sure the tip is clean. 

Now, turn the board 180 degrees and using solder, touch the tip to both the component and pad, and add a small amount of solder to the tip. Use the solder sparingly. If you get too much, use solder braid to remove any excess. 

Turn the board 180 degrees and solder the tacked side to complete. Always rotate the board to make soldering easier. Don't try to reach over the components as it can become a disaster.  

FIREWORKS EARRINGS

FIGURE 2. Fireworks LED placement
FIGURE 3. Battery Holder

Although the silk screen on the board lists the LEDs, it is small and hard to read. Check out Figure 2 to get a better look at the boards. Be sure and follow the parts list for the colors of the LEDs. You can start with any number, but I recommend keeping things in order starting with number one. All cathodes (normally, a small line is on the front or back of the LED) will be toward the left, or next to the number of the LED. Use the general guidelines mentioned previously for soldering these LEDs. 

Turn the board over and tack the single capacitor (it has no polarity) and the eight 150 ohm resistors. Finish soldering these components. Next, tack the microprocessor. There is a little indented dot on the micro indicating pin 1. Make sure this goes to pad 1 on the board. There is normally enough solder on the pads and the micro, so you don't need to add solder. Inspect with a loupe to insure proper soldering. Add solder sparingly to each pin and pad. If you get a solder bridge, use solder wick to remove any excess. (Most beginners use too much solder.) Finally, solder the battery holder. Make sure the stopping ears of the holder are toward the center of the board and not the edge. Otherwise, you won't be able to put in the battery (see Figure 3).

JACK O’ LANTERN EARRINGS

Refer to Figure 4 and the Parts List. Recall there are only 19 LEDs on this board. Follow the general instructions for the fireworks earrings.

EMOTICON EARRINGS

Refer to Figure 5 and the Parts List. Again, follow the general instructions discussed above.

FIGURE 4. Jack O' Lantern LED placement Figure 5. Emoticon LED placement


NOTE: All the LED cathodes will be facing left with the exception of # 23 which will be facing to the right. (This board is like trying to get 10 lbs of potatoes in a 5 lb bag.) This LED was reversed because I ran out of board space for traces. It was easier to reverse the diode than to design a multilayer board which can get expensive.    

USING THE EARRINGS

There is a small hole at the top to attach the earring wires or clips. Just add a CR1225 battery and the earrings should light and perform on their own. A couple of things can cause havoc (speaking from experience). An LED being reversed or shorted can cause other LEDs to light up that should not be lit. LEDs that are cold soldered can do the same thing.

POWER CONSUMPTION

When an LED is on, it is pulsed about 30 milliamps. Only one LED is on at a time, so the micro draws a minimal amount of power (less than .1 milliamps). However, the LEDs are not on 100% of the time and depending on the earring type, some sit silent for a period of time.  The CR1225 has 25 mAh of power. If one LED was on 100% of the time drawing 15 milliamps, the battery would power it for 3.2 hours. I would expect at least eight hours of operation. 

FOR THE BRAVE AND BOLD

For most of my projects, I add pads for anyone who wants to change the programming. Unfortunately, there was not enough room on the board for the pads. However, it can still be programmed via soldering wires (I use wire-wrap wire) to the programming pins, ground and Vcc.  A total of five wires are needed. These wires go to a PICkit 2 or 3 programmer. This is how I set up the faces and the fireworks.  

As a final check, I grounded one column and turned on each resistor separately, noting which LED turned on. Then, I grounded the second column, etc. Worksheets with the codes and LED numbers for the different versions are on the website since each earring has a different pattern to follow. 

Now, you can truly put on a HAPPY FACE!  NV

Parts List

Component Qty Description Mouser Part Numbers
EMOTICONS
Battery Holder 1 12 MM battery 712-BAT-HLD-012-SMT
C1 1 .1 uF 805 C0805C104K5RACTU
IC1 1 PIC16F627 SM 579-PIC16F627A-I/SO
Leds 1-2-15-16-17-18-19-20-21-22 10  Red 805 859-LTST-C171CKT
Leds 3-4-5-6-7-8-9-10-11-12 10 Yellow 805 859-LTST-C171KSKT
Leds 13 -14-23-24 4 Blue 805 859-LTST-C171TBKT
R1 - R8 8 100 ohm 805 RK73H2ATTD1000F
12 MM BATTERY 1 CR1225  
Ear Wires 1 See local craft store  
FIREWORKS
Battery Holder 1 12 MM battery 712-BAT-HLD-012-SMT
C1 1 .1 uF 805 C0805C104K5RACTU
IC1 1 PIC16F627 SM 579-PIC16F627A-I/SO
Leds 3-4-5-6-8-9-10-11-12 9  Red 805 859-LTST-C171CKT
Leds 1-2-23-24 4 Yellow 805 859-LTST-C171KSKT
Leds 17-18-19-20-21-22 6 Blue 805 859-LTST-C171TBKT
Leds 7-13-14-15-16 5 White 805 593-VAOL-S8WR4
R1 - R8 8 100 ohm 805 RK73H2ATTD1000F
12 MM BATTERY 1 CR1225  
Ear Wires 1 See local craft store  
JACK O'LANTERN
Battery Holder 1 12 MM battery 712-BAT-HLD-012-SMT
C1 1 .1 uF 805 C0805C104K5RACTU
IC1 1 PIC16F627 SM 579-PIC16F627A-I/SO
Leds 1-2-3-4-5-6 6  Red 805 859-LTST-C171CKT
Leds 7-8-9-10-11-12-13-14-15-16-17-18-19 13 Yellow 805 859-LTST-C171KSKT
R1 - R7 7 100 ohm 805 RK73H2ATTD1000F
12 MM BATTERY 1 CR1225  
Ear Wires 1 See local craft store  


Click Here to download Express PCB, code, schematic, and LED placement files for this project.

Click Here to go to the Nuts & Volts webstore and get the kit or see the ultra low production quality video.


Posted on 06/15 at 8:22 pm

Posted in: Developing Perspectives

Going Beyond Shallow Understanding

May 15  Bryan Bergeron

Thanks to readily available kits, DIY articles, and web resources, it’s a simple matter to cobble together a functional circuit with little real understanding of the underlying electronics. The circuit description for an audible siren kit might read something like “Q1 and Q2 form an astable multivibrator.” At some level, this may be adequate. However, if you’re interested in truly understanding an astable multivibrator — or any other circuit for that matter — you have to dig deeper.


There’s a cost, of course, for digging deeper. You have to invest the time to read about various oscillator circuits including the tradeof fs of each design, perhaps historical uses of the circuit, and perhaps applications beyond that of a siren. The payof f for going beyond the surface descriptions of circuits on a regular basis is the ability to intuit circuits. It’s a skill that I’d say is possessed by less than 1% of hobbyists.

Developing a deeper understanding of electronics often means looking into other systems. For instance, if you gain an understanding of a mechanical oscillator, many of the principles will transfer to an electronic version. Consider that mechanical damping has direct parallels with electric dampers, for example. In this regard, digging deeper of ten involves studying the history of engineering. 

My favorite historical topics are watches, clocks, and robotics — all of which predate electronics by over a century. By searching the Web — including the US Patent and Trademark Of fice site — I’ve found mechanical analogs for everything from batteries (springs) and voltage regulators (mechanical regulators) to ergonomic user inter faces (watch faces and winding stems). In some cases, I find myself wondering why per fectly good mechanical designs were replaced by inferior electronic circuits. I also wonder if there is anyone alive today capable of recreating the mechanical systems of a century ago. Of course, if you’re not comfor table with self-directed learning, there are schools of engineering that can give you a formal education in electronics. Whether or not that translates to the ability to intuit electronic circuits depends on the school and how you leverage your experience. That said, I’ve found hands-on experience the best teacher regardless of the learning environment. You have to get your hands dirty to truly understand electronics. So, get that soldering iron ready. NV


Posted on 05/15 at 9:47 am

Posted in: Nuts and Volts

The State of Arduino

May 15 

Massimo Banzi, co-founder of the Arduino Project gives a heads up about the state of Arduino and talks a little about the new sister brand they will introduce called Genuino.  Genuino (“genuine” in Italian) - perhaps named because of how easy it was to find knock-offs of the Ardunio... They also announced they will start a partnership up with Adafruit to manufacture and distribute Ardunio boards in the US.


At the beginning of July Arduino will celebrate Independence day as a bunch of classic Arduino and new boards will be available from Arduino stores and some distributors with the classic Arduino.cc brand in the US market and going into details with dates:

– Arduino WiFi Shield 101 from the 25th of June

–  Arduino Yún Shield available from the 25th of June – Adding Arduino Yún capabilities to any Arduino.

– Arduino Zero available from the 9th of July

 


Posted on 05/15 at 9:13 am

Posted in: Nuts and Volts

CHIP - The World’s First Nine Dollar Computer

May 15 

Back this Kickstarter for just under $10 and you get a computer with 1Ghz and 512MB of DDR3 RAM. C.H.I.P. is powerful enough to run real software, and handle the demands of a full GUI just as well as it handles attached hardware. CHIP also runs mainline Linux, which means it’s easier than ever to keep teaching it new tricks without inheriting a pile of kernel patches. Our favorite part about this kickstarter isn't just the price, its the fact that source code for the System on Chip and Power Management Chips used in C.H.I.P. will be all be open source.



Posted on 05/15 at 8:49 am

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